Hopkins Marine Station Student Paper

Title: The association between the chiton Cryptochiton stelleria (Middendorff, 1846) and the epizoic red alga Pleonosporium squarrosim Kylin in the Monterey Peninsula AreaStudent Author(s): McDermid, KarlaFaculty Advisor(s): Abbott, IsabellaPages: 21Location: Final Papers Biology 175HDate: June 1980 Keywords: symbiosis at the seashoreAbstract: The giant chiton, Cryptochiton stelleri (Middendorff, 1846) is known from northern Japan to southern California for its thick brick-red girdle covered by tufts of crimson calcareous bristles (Smith, 1975). close examination of this mollusk often reveals that Cryptochiton's dorsal surface also maintains a miniature forest of red algae. Pleonosporium squarrosum Kylin (Ceramiceae), the 2-3 cm tall red alga is a leading member of the chiton's epizoic community. The distribution of P. squarrosum is limited to pilings of docks at Friday Harbor, Washington (Kylin, 1925) and the backs of a few subtidal invertebrates in Monterey, California (Abbott and Hollenberg, 1976). P. squarrosum appears very selective in its habitat, yet common on the Cryptochiton despite an earlier report by MacGinitie and MacGinitie (1968) which indicated th Cryptochiton backs did not carry a distinctive flora or fauna. The purpose of this study was to investigate the obvious chiton-alga associaton -- its incidence, distribution, causality and natural history.Notes: Publ 1981, Veliger 23: 317-320